


Behavior Training

by suns_out_sleeps_in_ramblings



Category: Shall We Date?: Obey Me!
Genre: Bottom!Mammon, F/M, I just really like bottom!Mammon, Kissing, Light Dom/sub, Light Masochism, Light Sadism, Lucifer shows up for a hot second then leaves sorry guys, Mammon gets to be a cool and intimidating demon occasionally, Mammon is just so much fun to tease, Mammon's Masochism, Suggestive Themes, Switching, Top!MC, as a treat, basically they're both switches, but I won't lie to myself here he's a switch, oh yeah Mammon has fangs too, there's nothing explicit, yet - Freeform
Language: English
Status: Completed
Published: 2020-04-03
Updated: 2020-04-03
Packaged: 2021-02-23 03:43:50
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,354
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23405230
Author URL: https://archiveofourown.org/users/suns_out_sleeps_in_ramblings/pseuds/suns_out_sleeps_in_ramblings
Summary: Sometimes a rowdy puppy needs to be reminded of its place.
Relationships: Main Character/Mammon (Shall We Date?: Obey Me!), Mammon (Shall We Date?: Obey Me!)/Reader
Comments: 6
Kudos: 221





	Behavior Training

**Author's Note:**

> I have a type and it’s one(1) desperate idiot of a demon  
> Also, a quick side note for like all my obey me fics the demon bois have fangs just the little nubby ones y’know the cute kind you see in like every other anime series
> 
> I can’t even lie when I say this is super self-indulgent I just want to lovingly bully Mammon and kiss him all over his stupidly handsome and adorable face and call him a good boy okay I have my needs!

So, you made pacts with some demons, in fact, you had made pacts with most of the demons you were currently living with. The Avatars of Sin itself were demons of remarkable renown and power that could destroy the world if they so choose.

No one told you that it was basically like being hired as a babysitter to a bunch of extremely overpowered overgrown children.

In reality, it wasn’t all that bad. Over the course of your stay at the House of Lamentation, you picked up a few tricks on how to placate the demons under your command to save yourself a splintering headache on those days when even they became too much; Beel will do almost anything for some food, Asmodeus can be negotiated with if you offer beauty supplies or promise him a shopping trip to Majolish, Levi is so much of a hopeless otaku that if you so much as passively flirt with him he’ll retreat into his room for the next few hours talking to Henry and/or Ruri-chan about “devious normie tactics”, Satan will read any new spellbook you give him or he’ll bother Lucifer just for shits and giggles, and Belphegor is too busy either sleeping in some random corner of the house, hanging off of his older twin or helping Satan piss Lucifer off to really be too much of a concern.

But Mammon, the oh-so GREAT Mammon, the very first demon you managed to wrangle(blackmail) into a pact, he was still a bit of wild card since he more often than not follows any flight of fancy he comes up with in that greedy little adorably stupid head of his, and ropes you into helping him. Consequences be damned. 

You now understand why Lucifer worries about him so much more than his other brothers. This lovable idiot is taking years off of your already much shorter lifespan trying to keep him from getting killed by his brothers or cursed by some witch he pissed off with unpaid loans. He is so lucky he's cute otherwise you would have half a mind to actually let Lucifer string him up for the next 500 years. At least he makes an attractive chandelier. 

And yet, despite this migraine-inducing moron’s schemes and misplaced bravado, he somehow managed to worm his way into being your best friend and anchor of sanity during your stay in this literal “whole new world” you were dragged into for Diavolo’s grand ambition. Mammon may be a pain in the ass, but if there is one thing you admire about him, it’s his loyalty. He constantly placates his devotion to you as being nothing more than a simple generous favor of the GREAT Mammon, but he also constantly reasserts himself as your first man, your first pact and best friend because of course he is. He’s the best at everything, after all.

There was, however, one key trick to dealing with Mammon if his ideas were really too much for you to handle or he just needed an attitude check. A dominating attitude.

You had learned on your first day in the House of Lamentation that Mammon was a masochist and nearly all of his interactions with Lucifer only further confirmed that fact. You originally hadn’t thought much of that fact until a split-second decision caused you to activate your pact with him and force him to behave to save him from Lucifer’s wrath. 

You had been studying in your room with Mammon and the second eldest had insisted on trying to convince you to goof off instead of doing homework, which meant that Lucifer’s “Trouble Senses” started tingling and he burst into your room ready to punish his younger brother then and there. You managed to save both of your hides and convinced the eldest demon brother to leave his punishment in your hands and forced the Avatar of Greed into compliance.

Once you two were alone, you breathed a heavy sigh of relief before addressing Mammon. “Sorry for forcing the pact, dude, but you seriously need to think things through before you end up strung up in the staircase again..” When you didn’t hear a proper response from Mammon, you peered up from your own textbook and noticed that he seemed way more tense and fidgety than normal after dealing with Lucifer. You thought that you were maybe imagining a slight flush to his cheeks and his reddening ears, unconsciously leaning into his personal space, brushing away his bangs and placing the back of your hand to his forehead, nearly scaring the poor demon out of his skin at the close proximity. 

“Ahh!” You reflexively moved your grip to his shoulders and forced him down to prevent yourself from being flung off the bed by his superior strength. What you didn’t expect was to hear what sounded like a mix of a whine and moan coming from the demon you ended up inadvertently straddling and forcing onto your bed. Now you knew you weren’t imagining his blushing expression since you could feel your own blush crawling up your face at the compromising position.

Neither of you said anything as you just let yourselves stay where you were, Mammon’s mind running into a thousand different directions, all leading to dead ends and you were no better. You’d be lying if you said that you didn’t harbor a pretty strong attraction to the demon currently being pinned to your bed. He always found a way to endear himself by just being so dumbly cute and obvious with his jealousy towards his brothers giving you their attention and how some of them seemed to throw themselves at your feet every chance they got. (read: Asmo and Belphie) Mammon could seriously rival Levi as the Avatar of Envy when it came to matters involving you.

But why did hearing him make that noise make you want to hear it again? Was it simply his masochism bubbling up like it tended to do more times than some would deem appropriate? What even technically counted as appropriate when you were classified as literally all forms of a particular sin wrapped into a single entity?

It was only after seconds of agonizing silence that you finally broke the dam and asked him if he was okay. 

“Mammon, are you good down there?” You didn’t receive an answer from him, but the way he kept glancing at you before directing his eyes in every direction but directly at you said everything he couldn’t. You took an experimental leap of faith and slowly, so as not to startle the poor demon, removed your hands from his shoulders. His eyes followed your every move as you sat back and placed your hands directly beside his hips. You could see his expression flicker between expectant, nervous, and longing like he was silently begging you to do something. Anything!

“Why don’t we get back to studying? We need to finish this, and we don’t want Lucifer barging in on us again, now do we?” To anyone coming into the room, it looks like you’re attempting to crawl over towards a captive Mammon, but you didn’t mind those thoughts too much as you lightly hooked one of your hands into the front of his plain black shirt and lightly tugged him upwards to sit up. He never abandoned that adorably lost expression on his face as he anxiously waited for what you would do next.

“...No, I don’t want anyone else here. I want you all to myself.” Shy and honest were not usually used to describe Mammon’s character, but it seemed like only you could bring out his more reserved side. You wistfully smiled as you brought your hand up to affectionately ruffle and play with his already messy stark white hair, just the way he likes it. The demon’s embarrassed expression was replaced with a bright smile overtaking his face as he leaned into your touch and purred. You remember how you nearly squealed when you learned that demons could purr. Mammon was exactly like an overexcited child when he just let himself relax and soak in the affection you so readily dish out and it warmed your heart each time you saw his goofy little smile.

“Right, and if you do well, I can give you a reward.” He immediately perked up at the prospect of a reward, his cat-like demeanor switching to that of an excited puppy, desperate for their owner’s attention and love. You barely contained your stifled laughter at how easily his demeanor could change once you knew which buttons to press. “How does that sound?”

“Y-yes, please!” The arms that were nervously hovering over your body before now eagerly wrapped around your middle and pushed you up into Mammon’s embrace so his face was right in your chest. You could feel him smile against your skin and wondered just how in the three realms a demon was allowed to be this cute, the very idea seems so fundamentally opposite that it shouldn’t be allowed to exist. It didn’t escape your notice that his blush returned once more, you didn’t even try to contain your laughter at how eager he could be. Such a simple demon, really. His expression quickly changed to indignation as he was about to question what was so funny before he noticed the positively wicked smirk forming on your lips. You were planning something. “Then why don’t we add a little something extra?”

“W-w-what are youuu…?!” The words quickly died in his throat once you turned in his arms and settled yourself in his lap. You giggled at the sounds of Mammon choking on his own strangled pleas as you adjust yourself until you are as comfortable as can be. You fit against him like a puzzle piece, and you suppress a sigh as you bask in just how nice it feels to sit with him this way. You carefully grabbed his wrists and gently guided his hands to settle on your hips, a knowing smile adorning your face as you can literally feel Mammon’s internal body temperature skyrocket. Meanwhile, Mammon sounds like a fish out of water, garbling out incoherent nonsense and whining like an impatient pup. 

He would never hear the end of it if his brothers barged in on you two right now. Mammon can only imagine what his face looks like to you when he can barely form words right now with you sitting in his lap and leading him oh so gently on how he should hold you. A soft smile on your face as you place his trembling hands directly on your hips and he can hear his own breath hitch in his throat. Complete disbelief covers his face in a look caught somewhere between amazement and utter terror. If his luck was truly terrible like it seemed to be most of the time and he messed this one singular moment up then he would never forgive himself.

He kept his gaze locked on the door to the room, ready to pin you to the bed at a moment’s notice so it looks like he’s the one in control. He can take a scolding. Hell, he’d even take a beating from all of his brothers at once as long as none of them saw you subduing and disarming him with that innocent yet smug smile on your face. As long as he got to keep that smile of yours all to himself, he was willing to risk anything.

“Surely the Great Mammon can handle something like this, can’t he?” You threw a look over your shoulder as you leaned forward to look back at him, a sinful and devious smile contrasting Mammon’s look of surprise. Mocking him must have triggered something since the next thing you know, Mammon is pulling you back to his chest and burying his face in the crook of your neck. His breath is hot and heavy against your skin as it ripples across your now flushed skin at Mammon’s sudden brazen actions.

“You are really pushing your luck, babe…” 

Ok, that was certainly a first. Usually, Mammon was too nervous to address you by anything other than “human” and your own name when he wanted your attention, so you can’t deny that hearing him call you “babe” in that dangerous tone was making you feel some type of way. You swear you feel the drag of his canines against your skin, the notion of Mammon potentially biting and marking you sending a spark of desire through your system. You bite your lip in an effort to suppress the groan of wanton pleasure that threatens to tear itself out of your throat, instead, you only let out the slightest hitch in your breath. You weren't about to let him get too cocky now that he managed to pull a lucky stunt and catch you off-guard for a moment.

“Tempting a demon like this when you know how I feel about ya, you better be prepared for what could happen.” Oh, if that’s how he wants to play, then, by all means, you were ready to play. This fool hadn’t even begun to scratch the surface of you pushing your luck. 

“Since when have I ever made things easy for you, babe?” You mimicked his earlier endearment and could swear you heard him let out a low, animalistic and inhuman growl. “But, we can save all that fun stuff for later, we still have homework to finish.”

Mammon was about to start protesting until you turned around in his hold and cupped his face in your hands. “Ah ah ah, no buts! Unless you actually want me to force you to obey?” Your sweet voice darkened as you subtly dragged your nails against the edge of his jaw, igniting a blush fiercer than any you had seen from him before. It took every ounce of Mammon’s willpower not to just melt in your arms then and there, his earlier bravado completely vanishing in the wake of your threat. You felt him shudder under your touch and smirked at how he seemed to visibly lean into your touch for more. 

For being one of the most powerful demons in the entire Devildom, Mammon was amazingly sensitive. Your scent was so sweet in his nose, the feeling of how you fill out his arms as he hugs you, the subtle tingle of your nails against his skin, the stern look on your face yet sickeningly sweet voice as you threaten to force him to behave was flipping a lot of switches in Mammon’s head and sending heat down towards his little troublemaker. He may not be the smartest demon around, but even Mammon knows when he can’t win. He resigns himself to whatever fate you set out for him, comforted by the knowledge that at least you’ll make a conscious effort not to go too far. Even as the second strongest of his brothers he had his limits but he trusts you.

“You may be the Avatar of Greed, my dear Mammon, but don’t forget who really holds the power between the two of us.” Your smile curled into an almost devilish smirk as you felt something under you start to perk up. Damn, it was almost too easy to rile him up.

“Y-yes, ma’am…” Oh, you could get used to this. 

“Besides, don’t forget that the reward only comes if you behave yourself, and you much prefer being good for me, don’t you?” You barely suppress a laugh at the petulant whine you hear build in the back of the masochistic demon’s throat as you feel his skin bristle and shiver beneath your touch as you continue to lightly caress his face with the very tips of your fingers. Mammon makes for a masterpiece in his own right with his skin now ruddy and the begging, damn near pleading look in his eyes, accentuated perfectly by that adorable pout he’s sporting.

Damn, no wonder Mammon works as a model. He really is gorgeous. There was just something about Mammon in particular that ignited the desire to tease him with some sweet words of praise while you dominate him until he cries. You almost never even needed to force your pact with him as he usually obeyed your whims if you worded them in just the right way to appeal to his ego, save for him purposefully screwing around and getting into his usual brand of mischief.

Eh, it was probably because of how eager he was to please you that stirred these desires in your heart. He was just cute enough to want to lovingly fuck him into the mattress until he can’t think straight. But that’s a fantasy for another day, you still have to finish your homework for class tomorrow.

“And since we’ve already come this far, what do you say if we make the reward a chance to continue our little game? I’m sure your little friend could use some attention too.” He was quick to agree as he vigorously nodded, blushing at your mutterance of him being a “good boy” and the small pat on his head.

“Can I at least kiss you? Please? You smell so nice and feel so good against me. I’ll do anything you want, just let me kiss you…” Making Mammon beg would never get old. He sounded like he was about to start crying when you teased him first with a chaste kiss on his cheek before laughing at his apparent misery. 

“C’mon! You know I meant on the lips!” You did relent in your torture of cruelly denying him with a kiss on the lips after he begged a few more times. He groaned into the kiss as he cupped the back of your head and used his other arm to pull you even closer to him as his lips worked insistently against yours. Hell-bent on drinking in every part of your affection as if he needed it to survive. His kisses were exactly like him, greedy, impatient, always seeking more, a hint of sweetness mixed a lover’s longing and desire to please.

“That’s more like it.” He laughed in between the kisses he continued to steal from you until you finally put your foot down and returned to your homework. He whined again but complied on the condition that you stay in his lap as you worked. You were happy to accept and continued until you were all done, surprised at his newfound obedience. Although you did need to lightly reprimand him when you felt him begin to lightly kiss and nibble on your exposed skin out of sheer boredom.

However, as soon as you proclaimed the completion of the last problem and had set aside your materials for the night, Mammon used your lowered guard as an opening to begin his counter-assault on you as he flipped you onto your back, pinning you to the bed in the same way you had done to him previously. His eyes held a devious look befitting a demon and the completely wicked smile on his face showed off his fangs, which he made a show of licking and chuckling to himself darkly, knowing exactly how the sight tended to turn your thoughts to mush. Damn his demonic charms, he really did know you just as well as you knew him. From the angle he kept you at, you could have sworn the blues in his eyes had disappeared completely as his eyes seemed to flash gold, the sight of which stunned you into silence.

“You didn’t think I’d just let ya get away with teasing me like that and not get my revenge, did ya? Now it’s my turn, babe.” Light nips against the sensitive spot on your neck followed by a soothingly wet tongue interrupted your mental fascination with his shifting eye color before a lust-addled, shuddering moan escaped from your lips and a delightful shiver coursed through your body before you could think to stop it.

Hoo boy, you were in for a long night.

**Author's Note:**

> Yes yes I know that Mammon is a multi-faceted character with a lot of complexity that goes beyond him being the series' resident punching bag but sometimes a girl just wants to write a longwinded fic as a way of saying "I want to smooch a cute and greedy tsundere demon!" and there's nothing more to it than that!
> 
> (I also may be persuaded into writing the smut that most definitely follows after the end but we'll see if my fellow Mammorons want some thirst quenched for our boi)


End file.
